Traumatic acid – trans-2-dodecenedioic acid – is synthesized in plant tissues from polyunsa- turated fatty acids, linolenic (18:3) and linoleic (18:2) in response to wounding, pathogenes attack and herbivores. The key enzymes in the biosynthesis pathway of TA are lipoxygenases (LOXs) and hydro- peroxide lyase (HPL). From the numerous investigations it appears that this compound stimulates the cell divisions, wound healing and callus formation. Moreover, TA causes the increase of the content of photosynthetic pigments, monosaccharides and water-soluble proteins in plants’ cells. Molecular mecha- nisms of the activity of TA and its influence on plants’ metabolic processes haven’t been recognized till now. It is only known that TA induces the tyrosine phosphorylation of proteins with molecular weights 19, 20, 22, 26, 31, 42 and 74 kDa.